Chinese warships sent to fight piracy in waters off Somalia were stalked by an Indian attack submarine and the two sides became locked in a tense standoff for at least half an hour, mainland media reported yesterday. After rounds of manoeuvring during which both sides tried to test for weaknesses in the other's sonar system, the two Chinese warships managed to force the Indian submarine to surface. The Indian vessel left without further confrontation. The incident was reported by Qingdao Chenbao yesterday and was widely carried by major mainland websites such as Sina.com and QQ. Both Beijing and New Delhi were silent about the matter. This is the first reported military standoff between China and India since a bitter border war in 1962. The incident took place on January 15 in waters near the Bab Al-Mandab Strait, which separates Yemen and Djibouti, at the western end of the Gulf of Aden. The Chinese destroyers had picked up an unidentified submarine on their sonar, the report said. The Chinese navy soon identified it as a 70-metre-long vessel armed with 20 torpedoes. Although the report did not directly specify the model, it provided a file photo of a Kilo-class submarine belonging to the Indian navy, which fit the description. The submarine tried to evade the Chinese warships by diving deeper. But the warships continued the chase. The report said the Chinese ships sent an anti-submarine helicopter to help track the submarine, which had tried to jam the Chinese warships' sonar system. But the two destroyers eventually cornered the submarine and forced it to surface. The report said the submarine had been trailing the Chinese ships since they had entered the Indian Ocean on the way to Somalia. It said that at one point the Chinese commander even ordered the helicopter to have its anti-submarine torpedoes ready. The Indian submarine is believed to have been collecting electronic signals and sonar data from the Chinese warships. Such information would be crucial in naval conflicts. The two destroyers China sent to Somalia are among its most advanced warships. One of the destroyers, Haikou, was commissioned in 2005. It is rare for mainland media to report such a close encounter between the Chinese navy and foreign warships. Although deemed a provocative and unfriendly gesture, it was not unusual for one country to send submarines to collect other navies' information. In 2006, a Chinese submarine was detected stalking the US aircraft carrier Kitty Hawk near the Japanese island of Okinawa. The Chinese submarine eventually surfaced close to the US battle group.